Organisation Of Cells

Questions and Answers

Which type of organism is composed of only one cell?

Multicellular organism

Unicellular organism (correct)

Colonial organism

Eukaryotic organism

Eukaryotes can only be unicellular organisms.

False

What is the main function of chloroplasts in plant cells?

Conduct photosynthesis

Cells become _____ to perform specific functions through the process of differentiation.

specialised Signup and view all the answers

Match the following organelles with their primary functions:

Chloroplasts = Photosynthesis Mitochondria = Cellular respiration Ribosomes = Protein synthesis Nucleus = Genetic information Signup and view all the answers

Which of the following statements about cellular specialisation is true?

Division of labour increases efficiency within multicellular organisms. Signup and view all the answers

Flagella are structures used for movement in multicellular organisms.

False Signup and view all the answers

What term describes the breakdown of work into smaller specific tasks for maximum efficiency?

Division of labour Signup and view all the answers

What is the primary role of connective tissue?

To support and bind other tissues Signup and view all the answers

A high surface area to volume (SA:V) ratio is beneficial for diffusion in larger organisms.

False Signup and view all the answers

Name one example of an autotroph.

Plant or algae Signup and view all the answers

The main function of __________ in leaves is to regulate gas exchange.

stomata Signup and view all the answers

Match the types of tissues with their primary functions:

Epithelial = Covers and protects surfaces Muscle = Facilitates movement Nervous = Transmits signals Connective = Supports and binds other tissues Signup and view all the answers

What type of organism requires other organisms for nutrition?

Heterotroph Signup and view all the answers

Alveoli are responsible for gas exchange in the leaves of plants.

False Signup and view all the answers

What do vascular bundles in plant stems consist of?

Xylem and phloem Signup and view all the answers

A __________ obtains energy for carbon fixation from sunlight.

photoautotroph Signup and view all the answers

Match the isotopes with their functions in plants:

Carbon-14 = Tracks glucose production Potassium = Shows ion movement in roots Phosphorus = Reveals fertilizer uptake Oxygen-18 = Not used for tracking in this context Signup and view all the answers

Which structure allows for gas exchange in animal lungs?

Alveoli Signup and view all the answers

Plants release carbon dioxide during photosynthesis.

False Signup and view all the answers

What is the relationship between the size of an organism and its reliance on specialized structures?

Larger organisms rely more on specialized structures to meet their needs. Signup and view all the answers

The __________ is a group of organs that work together to perform a specific function.

organ system Signup and view all the answers

Which type of tissue would you expect to find in the walls of your heart?

Muscle Signup and view all the answers

What is the primary gas that diffuses into leaves during photosynthesis?

Carbon Dioxide Signup and view all the answers

Fish breathe by absorbing oxygen directly from the air through their gills.

False Signup and view all the answers

What conclusion did Jan Baptista van Helmont mistakenly reach regarding plant growth?

That plants grow by consuming soil. Signup and view all the answers

The __________ is a tissue that transports sugars throughout the plant.

phloem Signup and view all the answers

Match the animal with its gas exchange method:

Insects = Through spiracles Fish = Through gills Amphibians = Through skin Mammals = Through lungs and blood vessels Signup and view all the answers

What happens to water as it evaporates from the leaf surface?

It creates a concentration gradient. Signup and view all the answers

Cohesion refers to the attraction between different types of molecules.

False Signup and view all the answers

What primary role does the xylem perform in plants?

Transporting water and minerals. Signup and view all the answers

Joseph Priestly discovered that plants restore oxygen to the air after it has been used by __________.

animals or burning candles Signup and view all the answers

Which part of the heart receives oxygenated blood?

Left atrium Signup and view all the answers

Stomata are responsible for diffusion of carbon dioxide into plant leaves.

True Signup and view all the answers

What is the primary mechanism of water transport in xylem called?

Transpiration Signup and view all the answers

Match the following processes with their corresponding descriptions:

Cohesion = Bonding between like molecules Adhesion = Bonding between different substances Transpiration = Evaporation of water from leaves Active transport = Movement against a concentration gradient Signup and view all the answers

What is the main function of the digestive system?

Break down food into nutrients Signup and view all the answers

Osmosis involves the movement of sugars in plants.

False Signup and view all the answers

What does the term 'translocation' refer to in plant biology?

Movement of sugars from leaves to other tissues throughout the plant Signup and view all the answers

The _______ is the first part of the small intestine, where chemical digestion is very active.

duodenum Signup and view all the answers

Match the following digestive enzymes with their functions:

Lipase = Fats digestion Amylase = Carbohydrates digestion Peptidase = Proteins digestion Maltase = Maltose digestion Signup and view all the answers

Which of the following macromolecules is essential for normal growth and metabolic processes?

All of the above Signup and view all the answers

The left ventricle pumps oxygen-poor blood into the lungs for oxygenation.

False Signup and view all the answers

What is the primary role of the colon in the digestive system?

Absorption of water and electrolytes Signup and view all the answers

A _______ is a low molecular weight organic compound that is essential for normal metabolic processes.

vitamin Signup and view all the answers

What transports nutrients from the small intestine to the rest of the body?

Blood vessels Signup and view all the answers

The heart is responsible for filtering blood in the body.

False Signup and view all the answers

What do autotrophs require for energy production?

Sunlight Signup and view all the answers

Peristalsis is the series of involuntary contractions that occur in the _______ tract.

intestinal Signup and view all the answers

Which of the following nutrients is primarily absorbed in the ileum?

Vitamin B12 Signup and view all the answers

What is the primary function of white blood cells?

Help defend the body against bacteria and viruses Signup and view all the answers

Capillaries are the largest blood vessels in the body.

False Signup and view all the answers

What is the role of the xylem in plants?

Transport water and inorganic substances Signup and view all the answers

The stomata are surrounded by two _____ cells.

guard Signup and view all the answers

Match the following statements with the correct circulatory system:

Closed circulatory system = Examples include fish and amphibians Open circulatory system = Examples include insects and spiders Signup and view all the answers

Which of the following describes the capillary function?

They link arterioles to veins Signup and view all the answers

The root system's main function is to produce glucose for plant growth.

False Signup and view all the answers

What is the disadvantage of a closed circulatory system?

Requires more energy for blood distribution Signup and view all the answers

The _____ mesophyll is composed of loosely packed cells to allow gas exchange.

spongy Signup and view all the answers

Which of the following statements about blood composition as it moves through the kidney is correct?

Carbon dioxide levels decrease Signup and view all the answers

Study Notes

Organisation of Cells

All prokaryotes are unicellular; eukaryotes can be unicellular or multicellular.
Unicellular organisms include archaea, bacteria, and protozoa; they perform all life processes.
Colonial organisms consist of individual cells living closely to ensure survival without specialization.
Multicellular organisms have specialized cells that depend on each other for survival and efficiency.
Cellular specialization allows diverse functions to be performed simultaneously in multicellular organisms.
Organelles such as chloroplasts conduct photosynthesis and contain chlorophyll for glucose production.
Mitochondria perform cellular respiration, generating ATP as the energy currency of the cell.
Ribosomes, found in rough ER, are responsible for protein synthesis.

Tissues, Organs, and Systems

Cell differentiation enables specialization for specific functions, triggered by internal or external stimuli.
Organ: a structure composed of tissues that perform specific functions.
Tissue types: connective, epithelial, muscle, and nervous.
Organ system: a group of organs working together to carry out distinct functions.
Hierarchical organization in multicellular organisms includes cells → tissues → organs → organ systems → organisms.

Size and Surface Area

As an object increases in size, both surface area and volume grow, but the surface area-to-volume (SA:V) ratio decreases.
High SA:V ratios facilitate diffusion; low SA:V ratios necessitate specialization to meet metabolic needs.

Nutrient and Gas Requirements

Autotrophs synthesize their own food from inorganic materials (e.g., plants and algae).
Heterotrophs obtain energy by consuming other organisms (e.g., animals and fungi).
Photoautotrophs use sunlight for energy; chemoautotrophs derive energy from inorganic chemical reactions.

Plant Structure and Function

Leaves are plant organs with layers like mesophyll, rich in chloroplasts for photosynthesis.
Stomata are pores surrounded by guard cells, regulating water loss during transpiration.
Stems connect roots and leaves, containing xylem and phloem for nutrient and water transport.
Xylem transports water upward, while phloem distributes sugars from leaves to other plant parts through the source-to-sink model.

Gas Exchange

Gas exchange involves oxygen and carbon dioxide; oxygen maintains cellular respiration, while carbon dioxide needs removal to prevent toxicity.
Alveoli in mammals enable gas exchange; they are thin-walled sacs surrounded by capillaries facilitating diffusion.
In plants, gas exchange occurs via stomata where carbon dioxide enters for photosynthesis and oxygen exits.

Transpiration and Nutrient Transport

Transpiration-cohesion-tension theory explains water transport in plants; cohesion keeps water molecules linked as they rise in xylem.
The structure of phloem (consisting of living tissue with sieve plates and companion cells) allows sugar movement throughout the plant.
Source-to-sink theory emphasizes the transport of sucrose from production areas to growth areas.

Digestion

Digestion breaks down food into absorbable nutrients; it involves both physical (chewing, peristalsis) and chemical (enzyme action) processes.
Nutrients, minerals, and water are absorbed primarily in the small intestine, specifically through the walls of villi.
The digestive process includes sections of the small intestine: duodenum (chemical digestion), jejunum (nutrient absorption), and ileum (water-soluble vitamin absorption).

Comparisons

Organisms consist of four biological macromolecules: carbohydrates, lipids, proteins, and nucleic acids, primarily made of CHONPS (carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur).

Transport Systems

The circulatory system, comprising the heart, blood, arteries, veins, and capillaries, transports oxygen and nutrients and removes waste.
The heart consists of four chambers: left/right atria and left/right ventricles, facilitating blood circulation.
Blood serves three primary functions: transport, protection, and regulation of body temperature, with plasma comprising 90% water and 10% other substances.### Blood and its Components
Plasma is essential in treating burns, shock, trauma, and medical emergencies due to its proteins and antibodies.
Therapies for rare chronic conditions like hemophilia and autoimmune disorders utilize proteins and antibodies from plasma.
Red blood cells, produced in red bone marrow, are disk-shaped and transport oxygen and carbon dioxide for 120 days.
White blood cells (leukocytes) protect against bacteria and viruses; they create antibodies through special proteins that identify foreign materials.
Platelets are fragments crucial for blood clotting; they adhere to broken cells and secrete clotting factors to form clots.

Blood Vessel Types

Arteries transport oxygen-rich blood away from the heart; they have thick, elastic walls to withstand high pressure.
Veins bring oxygen-poor blood back to the heart; they have thinner walls and larger lumens.
Capillaries are the smallest blood vessels with one-cell-thick walls, vital for nutrient and oxygen delivery as well as waste absorption.

Plant Structure and Vascular Systems

Autotrophs (plants) possess vascular, root, and shoot systems for structure and transport.
The vascular system consists of xylem, transporting water and inorganic substances, and phloem, moving organic nutrients like sucrose.
Root systems anchor plants and efficiently absorb water/minerals, with a branching structure to maximize surface area.
Stem and shoot systems support leaves for photosynthesis and flowers for reproduction, facilitating fluid transport.
Leaves contain stomata, controlled by guard cells, which regulate gas exchange and water loss.

Gas Exchange in Plants and Animals

Investigate how gases move between internal and external environments.
Closed circulatory systems circulate blood via enclosed vessels; found in vertebrates like fish, amphibians, reptiles, and mammals.
Open circulatory systems involve pumping hemolymph into a hemocoel surrounding tissues; common in molluscs and arthropods.

Characteristics of Circulatory Systems

Closed systems deliver fluids directly to cells; open systems allow fluids to bathe organs for diffusion.
Common functions of both systems include transporting oxygen, nutrients, waste products, and immune cells.

Advantages and Disadvantages of Closed Circulatory Systems

Advantages: Efficient oxygen delivery, better waste removal, pressure from heart enhances circulation, and an independent lymphatic system.
Disadvantages: Higher energy requirements and greater system complexity.

Changes in Transport Medium Composition

During cellular respiration, oxygen and glucose decrease, while carbon dioxide and urea increase in composition as blood passes through various organs:
- Heart: O2 decreases, glucose decreases, CO2 increases, urea increases.
- Brain: O2 decreases, glucose decreases, CO2 increases, urea increases.
- Lungs: O2 increases, glucose decreases, CO2 decreases, urea increases.
- Kidney: O2 decreases, glucose decreases, CO2 increases, urea increases.
- Small Intestine: O2 decreases, glucose increases, CO2 increases, urea increases.

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Description

Explore the fascinating world of cells with this quiz on cell and organelle structures. Learn about the differences between prokaryotes and eukaryotes, and the significance of unicellular organisms. Delve into the characteristics of archaea, bacteria, and protozoa in this engaging assessment.